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Document type:
Zeitschriftenaufsatz 
Author(s):
Mayrhofer, K. J. J.; Arenz, M.; Blizanac, B. B.; Stamenkovic, V.; Ross, P. N.; Markovic, N. M. 
Title:
CO surface electrochemistry on Pt-nanoparticles: A selective review 
Abstract:
Oxidn. of CO on Pt nanoparticles ranging in size from 1 to 30 nm was studied in acid electrolytes. Pt nanoparticles, characterized by TEM, are not perfect cubo-octahedrons and large particles have rougher surfaces than small particles. The importance of defect sites for the catalytic properties of nanoparticles was probed by using IR reflection absorption spectroscopy (IRAS) and rotating disk electrode. From IRAS expts., by monitoring how the vibrational frequency of a-top CO (vCO) as well as the concomitant development of dissolved CO2 are affected by the no. of defects on Pt nanoparticles, probably defects play a significant role in CO clustering on nanoparticles, causing CO to decrease/increase in local coverage, which results in anomalous red shift/blueshift vCO frequency deviations from the normal Stark-tuning behavior. The obsd. vCO deviations are accompanied by CO2 prodn., which increases by increasing the no. of defects on the nanoparticles, i.e., 1 ≤ 2 < 5 .mchlt. 30 nm. Probably the catalytic activity for CO adlayer oxidn. (CO stripping) is predominantly influenced by the ability of the surface to dissoc. H2O and to form OHad on defect sites. The catalytic activity of Pt nanoparticles for CO oxidn. under the condition of continuous CO supply to the surface depends on the pre-history of the electrode. If the surface is precovered by CO, the particle size has a negligible effect on CO oxidn. However, on an oxide-precovered surface CO bulk oxidn. increases with decreasing particle size, i.e., with increasing oxophilicity of the particles. The authors found, if specific sites on the surface are active for OH adsorption, then the electrocatalytic activity for CO oxidn. changes as the concn. of these sites changes with particle size. [on SciFinder(R)] 
Keywords:
Nanoparticles (CO electrochem. oxidn. on Pt-nanoparticles of various size in acid solns.) Oxidation catalysts (electrochem. Pt-nanoparticles for CO) Particle size (nanoscale CO electrochem. oxidn. on Pt-nanoparticles of various size in acid solns.) IR spectra (of CO adsorbed on Pt-nanoparticles) Oxidation (of CO on Pt-nanoparticles of various size in acid solns.) carbon monoxide electrochem oxidn platinum nanoparticle IR spectra 
Congress title:
CAN 143:428685 72-2 Electrochemistry Materials Science Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, CA, USA. Journal 0013-4686 7440-06-4 (Platinum) Role: DEV (Device component use), USES (Uses) (CO electrochem. oxidn. on Pt-nanoparticles of various size in acid solns.); 7601-90-3 (Perchloric acid) Role: NUU (Other use, unclassified), USES (Uses) (CO electrochem. oxidn. on Pt-nanoparticles of various size in solns. contg.); 630-08-0 (Carbon monoxide) Role...    »
 
Journal title:
Electrochim. Acta 
Year:
2005 
Journal volume:
50 
Journal issue:
25-26 
Pages contribution:
5144-5154